High frequency system



June 4, 1940. A. wlEssNL-:R 2,203,315

HIGH FREQUENCY SYSTEM Find Harsh s, 19:58

i Patented June 4, 1940 UNITED STATES PATENT OFFICE 2,203,316 HIGH FREQUENCY SYSTEM Alfred "Wiessner, Berlin, Germany, assis-nor to C. Lorenz Aktiengesellschaft, Berlin-Tempelhof, Germany, a company Application March 8, 1938, Serial No. 194,555y In Germany MarchvlZ, 1937 1 Claim.

Vl follows that transmission becomes impossible above agiven frequency range.

The present invention consists in certain features of novelty which will be fully understood from the following description and be pointed out in the appended claim, reference beingmade to the accompanying drawing, in which- Fig. 1 diagrammatically illustrates different A curves of attenuation in response to frequency, while Fig. 2 is a diagrammatical representation of an arrangement according to the invention.

Referring rst to Fig. 1, the continuous curve I shows .the attenuation of a two-conductor line of a cable which is employed for high frequency intelligence transmission. The attenuation is plotted in dependency upon frequency. It is a well known measure 'to combine the two-conductor lines of a cable to phantom circuits (fourwlre units, eight-wire units and the like) in order to provide a larger number vof channels for the low frequency message transmission and to employ these channels for message transmission independently of the side or component circuits. However, this is possible under such conditions only that the circuits used for forming such phantom units are provided with corresponding bal- (ci. lis- 15) cables which are adapted for high frequency communication and to effect intelligence transmis- 'sion thereover at a frequency which is higher than that employed on the side circuits. The dashed curve II of Fig. 1 shows an attenuation curve which has been obtained in a test with side circuits combined to a four-wire unit, for example. The frequency of the alternating carrier currents traveling along the side circuits is then located in the range between the points a 10 and b of the frequency spectrum, while the frequency range between the points c and d is employed for transmission along the combined side circuits.

The pertaining circuit diagram is shown in Fig. 15

' 2. Two two-wire lines AB and CD of a high frequency conduction cable associated with the repeaters I, 2, 3 and 4 are-connected as a phantom circuit through the repeaters 5 and 6. The message transmission is effected over this cir- 20 cuit at a frequency which is higher than that of the side circuits, so that cross-talk freedom is l not necessarily required between the four-wire units and said circuits, on the contrary, the alternating message currents may be separated in 25 filter devices or the like according to any known methods. It is possible to combine four-wire units to eight-wire units in the same manner as above described.

What is claimed is:

The method of message transmission over physical cable pairs utilizing high frequency oscillations which includes the steps of connecting the cable pairs in phantom, impressing high freoscillations'at which said upper frequency the 40 side lines approach maximum attenuation.

ALIE'RED WIESSNER. 

